Ignition wire bursts into flames

[Tinster]

I had to replace a broken choke cable set when the 2 fires happened. First time, I did not touch any wire. Everything running fine. I removed the 2 screws that hold my small dash to the frame and angled the tiny dash forward to gain access to the choke cable set-nut behind the dash. Installed the choke cables, angled the tiny dash back into position and the hot wire from the ignition switch all the way to the PowerBlock Hot-hub exploded in flames and smoke and melted. Yes, ditz had battery connected.

Second attempt: Disconnected battery, same procedure, rotated small dash downward but not off frame. Installed new ignition hot wire, rotated small dash back up. Touched red battery cable to battery. Yellow primary ignition hot wire blew up in flames and smoke again. I am stumped. Any help appreciated. The primary wire is unfused.

 

[Andrew Mace]

First thought is that you have a pinched wire or something else causing a major short circuit / power-to-ground connection. I've been through similar situations on a TR250, where everything behind the dash seems to be in very close quarters!

 

[Tinster]

Yes Art, had to be a major short and it was. Full power of battery directly into the dash steel frame behind the ign. switch. Both fires melted the copper primary ignition wire. I just a bit ago found the cause. I figured the full power of the battery was needed to melt a No8 copper wire that fast. I slowly reversed my procedure. BINGO. In the upright position, the Hot terminal of my ignition switch just grazes the dash steel frame. Major short. Easy fix- rotate the key switch 30 degrees.

 

[TomMull]

Sorry, missed last post. This is of course moot. Glad you found it. Tom Agreed. I'd put in yet another wire and check for continuity between that wire and frame (or any ground) with an ohm meter. There should be none (ignition off and battery disconnected). Follow to each connection until you find the short. It will most likely be close by. Tom

 

[KVH]

Dale, is that your TR6 in the Photo? Dash looks nice. Is that the same TR you were having so much trouble with, or a different one?

 

[Tinster]

Dale, is that your TR6 in the Photo? Dash looks nice. Is that the same TR you were having so much trouble with, or a different one?

Yup same car. Thanks on the dash- I designed it and had it cut from Puerto Rico native Teak. It took me 4 years to restore the '69 TR6 to reliable running condition. Been having fun driving it for over a year without a break down.

d

 

[tdskip]

Glad you found it Dale

 

[startech47]

Dale,

I glad the damage was so localized. I little wire can make a lot of smoke. I had visions of the garage at knee height after the fire was extinguished. Happy motoring.

 

[TonyPanchot]

I have found that a good wrap with electrical tape on all terminals in close prox to the metal dash frame is a good measure IMHO

 

[Tinster]

I have found that a good wrap with electrical tape on all terminals in close prox to the metal dash frame is a good measure IMHO

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Houston- We have lifttoff" !! HooRah HooRay. Dashboard wiring harness repaired, new, twin Stromberg choke cables installed -
The ancient old bucket of bolts '69 Triumph TR6 Amos started on very first crank of the key. YEEHAW!!!

Many thanks to all who contributed advice, including Dan masters.

Terminals either wrapped or liquid plastic. And yes, the primary ignition wire melted due to a short will certainly 1/2 fill a garage with smoke. I did it twice.

Amos humming away in the garage during this monsoon rain day.

 

[tdskip]

Great Dale - enjoy driving her once I dries out.

 

[14dna]

Dale;

You look good in that car!
Happy Motoring!

Dave

 

[71MKIV]

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